共查询到20条相似文献,搜索用时 46 毫秒
1.
A newly released processless Gafchromic EBT3 film was investigated for its response to ultraviolet radiation (UVR) at three different wavelengths: 365 (UVA), 302 (UVB) and 254 nm (UVC). The change in the film's optical density was dependent on the radiance exposure and UV wavelength and was found to correlate with the UV intensity. The dynamic range of the EBT3 films is ~5 to ~60 J/cm2 for UVA and UVB and ~5 to ~300 J/cm2 for UVC. The dose sensitivity of EBT3 films for UVA and UVB radiation was approximately 10 times higher than that for UVC radiation. The results indicate the suitability of EBT3 films for quantitative and qualitative measurements of UVR exposure. 相似文献
2.
E. V. Grabovski P. V. Sasorov A. P. Shevelko V. V. Aleksandrov S. N. Andreev M. M. Basko A. V. Branitski A. N. Gritsuk G. S. Volkov Ya. N. Laukhin K. N. Mitrofanov V. G. Novikov G. M. Oleinik A. A. Samokhin V. P. Smirnov I. Yu. Tolstikhina I. N. Frolov O. F. Yakushev 《JETP Letters》2016,103(5):350-356
The effect of induced transparency of thin Al foils radiatively heated by intense extreme ultraviolet (EVU) radiation has been observed. The radiation of the plasma of Z-pinches appearing under the compression of tungsten liners at the Angara-5-1 facility has been used as the radiation that heats the Al foil (peak illumination on the foil ~0.55 TW/cm2) and is transmitted through it. The photoabsorption has been studied in the formed aluminum plasma at temperatures of ~10–30 eV in the density range of ~1–20 mg/cm3 in the wavelength range of ~5–24 nm. Absorption lines of Al4+...7+ ions have been identified in the experimental spectrum. In addition, radiative gas-dynamic simulations of the foil heating and expansion have been performed taking into account radiation transfer processes. 相似文献
3.
4.
V. M. Apatin V. N. Lokhman D. D. Ogurok D. G. Poydashev E. A. Ryabov 《Journal of Experimental and Theoretical Physics》2011,112(1):1-9
The results of the investigation of the multiphoton ionization of (CF3I)
n
clusters by ultraviolet laser radiation are reported. The yields of the I2+ and I+ ions, which are the products of the multiphoton ionization, have been measured as functions of the intensity of the ultraviolet
radiation at the wavelengths of 308 and 232.5 nm. The degree of multiphoton ionization has been determined and appears to
depend on the wavelength of radiation. The velocity distributions of the products have been measured in detail for various
wavelengths and various polarizations of radiation. The anisotropy parameters of the velocity distributions of the produced
ions and their kinetic energy have been determined. After analysis of the data, a mechanism of the multiphoton ultraviolet
ionization of the clusters under investigation has been proposed. This mechanism depends on the used wavelengths. 相似文献
5.
Information concerning the effect of irradiation on the optical properties of materials in the infrared, sub-mm-and mm-wavelength regions is of increasing importance in fusion plasma diagnostics. The radiation induced transmission loss of a number of materials has therefore been investigated at wavelengths in the ranges 200 nm to 40 μm and 0.23 to 2.0 mm. The samples were irradiated with doses of up to 1010 rad in a nuclear reactor. While germanium shows considerable transmission loss at doses as low as 106 rad, and the transmission of TPX decreases at 109 rad, other materials, e.g. fused quartz and possibly ZnSe, exhibit sufficient radiation hardness for use in fusion plasma diagnostics. 相似文献
6.
Stimulated infrared (IR) emission from a condensed dielectric medium under exposure to a giant pulse of a ruby laser is reported.
This effect was predicted in the theoretical paper [1]. Experimental studies were carried out for a number of molecular liquids
in two experimental geometries. In the first case (“in transmission” geometry) the propagation direction of the detected IR
radiation coincided with that of the exciting radiation. In the second case IR radiation generated was detected in the opposite
direction. The angle of divergence of IR radiation was found to be of 10−2 rad, while the conversion efficiency with respect to the pumping intensity depended on the type of molecular liquid and varied
in the range of 0.05–0.6%. Possible microscopic mechanisms of generation of IR radiation under pumping of the dielectric medium
with visible or ultraviolet (UV) radiation are analyzed. 相似文献
7.
《Current Applied Physics》2009,9(1):234-237
Sputtered deposited thin films of AlN:Pr and GaN:Pr emit in ultraviolet–visible and visible regions of the spectrum, respectively, under electron excitation in cathodoluminescence apparatus. The goal is to study the ultraviolet emission from Pr+3 when doped in nitride semiconductor hosts. Luminescence peaks at a wavelength of 295 nm (4.2 eV), 335 nm (3.7 eV) and 385 nm (3.24 eV) are observed as a result from 1S0 → 1G4, 1S0 → 1D2 and 1S0 → 1I6 transitions, respectively. However the 1S0 → 1G4 and 1S0 → 1D2 transitions are not observed when Pr+3 is doped in GaN host. The bandgap of GaN absorbs the ultraviolet radiation emitted from Pr+3 and hence GaN can be used as ultraviolet filter for radiation shielding and protection purposes. AlN is transparent to ultraviolet due to its wide bandgap of 6.2 eV. 相似文献
8.
S.F. Hanna R. Barron-Jimenez T.N. Anderson R.P. Lucht J.A. Caton T. Walther 《Applied physics. B, Lasers and optics》2002,75(1):113-117
An all-solid-state continuous-wave laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule
has been developed and demonstrated. The single-mode, tunable output of a 10-mW, 395-nm external-cavity diode laser (ECDL)
is sum-frequency-mixed with the output of a 115-mW, frequency-doubled, diode-pumped Nd:YAG laser in a beta-barium-borate crystal
to produce 40 nW of tunable radiation at 226.8 nm. The wavelength of the 395-nm ECDL is then scanned over NO absorption lines
to produce fully resolved absorption spectra. Initial results from mixtures of NO in nitrogen in a room-temperature gas cell
are discussed. The estimated NO detection limit of the system for a demonstrated absorption sensitivity of 2×10-3 is 0.2 ppm per meter of path length for 300 K gas. The estimated accuracy of the measurements is ±10%.
Received: 25 February 2002 / Revised version: 31 May 2002 / Published online: 8 August 2002 相似文献
9.
Luminescence efficiency of self-activated CaWO4 under 147 nm vacuum ultraviolet (VUV) radiation excitation is about 90% of that of BaMgAl10O17:Eu2+ (BAM), the commercial blue plasma display panel (PDP) phosphor. However, the color purity and the particle size of the former needs substantial modification before it can be considered for application in PDP. CaWO4:Tm exhibits Tm3+ emission peaks in the blue region due to energy transfer from WO4 to Tm3+ ions but the overall emission intensity under 147 nm excitation is reduced when compared to that of CaWO4. 相似文献
10.
N. N. Vedenkin G. K. Garipov P. A. Klimov V. V. Klimenko E. A. Mareev O. Martinez V. S. Morozenko I. Park M. I. Panasyuk E. Ponce H. Salazar V. I. Tulupov B. A. Khrenov I. V. Yashin 《Journal of Experimental and Theoretical Physics》2011,113(5):781-790
Millisecond ultraviolet (240–400 nm) and red-infrared (610–800 nm) flashes were detected in the nighttime atmosphere with the scientific payload installed onboard the Universitetsky-Tatiana-2 micro-satellite. Flashes with various numbers of photons, from 1020 to 1026, were detected within the atmospheric area 300 km in diameter observed by the detector. The flashes differ in duration and temporal profile: from single short flashes ~1 ms in duration to flashes with a complex profile more than 100 ms in duration. Different global geographic distributions are observed for flashes with different numbers of photons. Flashes with fewer than 1022 photons are distributed uniformly over the Earth’s map. Flashes with more than 1022 photons are concentrated near the equator and above the continents. Series of flashes were observed in one turn of the satellite when flying not only over thunderstorm regions but also over cloudless ones. The flash number distribution has been derived from the ratio of the numbers of red-infrared and ultraviolet photons. As applied to discharges in the upper atmosphere, whose glow is dominated by the emission in the first and second positive systems of molecular nitrogen bands (1PN2 and 2PN2), this distribution is equivalent to the flash altitude distribution in the atmosphere. The observed ratio of the numbers of photons in red-infrared and ultraviolet flashes agrees with the calculated one for electric discharges at altitudes higher than 50 km. In-orbit measurements of the charged particle flux (with a threshold energy for electrons of 1 MeV) provide no evidence for a synchronous occurrence of an ultraviolet flash and a burst in the particle flux in the orbit. 相似文献
11.
This study has been carried out using synchrotron radiation, time-resolved luminescence ultraviolet and vacuum ultraviolet spectroscopy, optical absorption spectroscopy, and thermal activation spectroscopy. It has been found that, in scintillation spectrometric crystals LaBr3: Ce,Hf characterized by a low hygroscopicity, along with Ce3+ centers in regular lattice sites, there are Ce3+ centers located in the vicinity of the defects of the crystal structure. It has also been found that the studied crystals exhibit photoluminescence (PL) of new point defects responsible for a broad band at wavelengths of 500–600 nm in the PL spectra. The minimum energy of interband transitions in LaBr3 is estimated as E g ~ 6.2 eV. The effect of multiplication of electronic excitations has been observed in the range of PL excitation energies higher than 13 eV (more than 2E g ). Thermal activation studies have revealed channels of electronic excitation energy transfer to Ce3+ impurity centers. 相似文献
12.
研究了埋氧注氮对部分耗尽SOI PMOSFET顶栅氧的总剂量辐射硬度所造成的影响。注入埋氧的氮剂量分别是8×1015 , 2×1016 和1×1017cm-2。实验结果表明,辐照前,晶体管的阈值电压随氮注入剂量的增加向负方向漂移。在正2V的栅偏压下,经5×105 rad(Si)的总剂量辐照后,同埋氧未注氮的晶体管相比,埋氧注氮剂量为8×1015 cm-2的晶体管呈现出了较小的阈值电压漂移量。然而,当注氮剂量高达2×1016 和 1×1017cm-2时,所测大多数晶体管的顶栅氧却由于5×105 rad(Si)的总剂量辐照而受到了严重损伤。另外,对于顶栅氧严重受损的晶体管,其体-漏结也受到了损伤。所有的实验结果可通过氮注入过程中对顶硅的晶格损伤来解释。 相似文献
13.
14.
V. A. Pustovarov B. V. Shul’gin M. Kirm M. M. Kidibaev A. A. Zhamangulov 《Optics and Spectroscopy》2000,88(5):713-717
Luminescence and excitation spectra of doped LiF and NaF crystals are studied by time-resolved optical and luminescent vacuum ultraviolet (VUV) spectroscopy (2–40 eV energy range, T=10–295 K) with the use of synchrotron radiation of the X-ray and the VUV ranges and pulsed electron beams. Spectral kinetic parameters of luminescence and energies of excited states of U6+ ions are determined. The dominant role of the electron-hole mechanism for energy transfer to impurity centers is established. The effect of multiplication of electronic excitations is clearly manifested for E > 25 eV in NaF:U, Cu crystals and determines their high scintillation yield (137% relative to Tl:CsI when detected in the current regime). 相似文献
15.
Two new methods are proposed for determining the polarization of vacuum ultraviolet radiation which permit the determination
of an arbitrary polarization mode for photons with energies of 10–100 eV. The essence of these methods is to create and detect
a nonequilibrium population of the magnetic sublevels of atoms and molecules excited by the original VUV radiation and then
determine the polarization of this radiation based on these measurements in accordance with known formulas.
Zh. Tekh. Fiz. 69, 115–122 (September 1999) 相似文献
16.
S. A. Bulgakova I. P. Ivanov A. Ya. Lopatin L. M. Mazanova 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2008,2(3):491-495
Binary and ternary copolymers of (meth)acrylic monomers of different chemical constitution are synthesized. The influence of the composition and molecular weight of copolymers on the sensitivity and contrast of resists based on them under exposure to extreme ultraviolet radiation (λ ~ 13 nm) is investigated. A resist having a radiation sensitivity of 0.6–1.0 mJ cm?2 and contrast coefficient γ = 1.5 is developed. 相似文献
17.
B. Couillaud L.A. Bloomfield J.E. Lawler A. Siegel T.W. Hänsch 《Optics Communications》1980,35(3):359-362
Doppler-free saturated absorption spectroscopy has been used to study the ultraviolet HgI transitions 63P0-63D1 at 296.73 nm and 63P0-61D2 at 296.76 nm. The required tunable ultraviolet radiation was produced by a ring cavity cw dye laser with intracavity ADA frequency doubler. The isotope shifts of the 63P0 -63D1 line for naturally abundant mercury have been measured to within a few MHz. 相似文献
18.
在10-3Pa的高真空环境下,利用355nm的紫外脉冲激光以低于石英基片零概率损伤阈值的能量密度对其进行重复多次的全口径扫描,目的是为了研究石英基片在接受不同剂量的紫外激光辐照后其抗损伤能力的变化和原因.通过辐照过程中损伤点的扩展程度以及辐照后的抗损伤测量表明,高真空环境下紫外脉冲激光辐照后的石英基片抗损伤能力明显降低,降低的幅度更多的与其接受激光辐照的次数有关,辐照能量密度的影响相对较小;通过荧光及X射线光电子能谱(XPS)检测发现,紫外脉冲激光辐照后石英基片表面氧缺位的增加是导致其抗损伤能力下降的主要原因,其程度也直接与接受辐照的紫外脉冲激光剂量相关. 相似文献
19.
Characterization of ZnO nanowire field-effect transistors and exposed to ultraviolet radiation
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A ZnO nanowire (NW) field-effect transistor (FET) is
fabricated and characterized, and its characterization of
ultraviolet radiation is also investigated. On the one hand, when
the radiation time is 5~min, the radiation intensity increases
to 5.1~μ W/cm2, while the saturation drain current (I_\rm
dss) of the nanowire FET decreases sharply from 560 to 320~nA. The
field effect mobility (μ ) of the ZnO nanowire FET drops from
50.17 to 23.82~cm2/(V.s) at V_\rm DS=2.5~V, and
the channel resistivity of the FET increases by a factor of 2. On
the other hand, when the radiation intensity is 2.5~μ W/cm^2
, the DC performance of the FET does not change significantly with
irradiation time (its performances at irradiation times of 5 and
20~min are almost the same); in particular, the I_\rm dss of NW FET
only reduces by about 50~nA. Research is underway to reveal the intrinsic
properties of suspended ZnO nanowires and to explore their device
applications. 相似文献
20.
The present paper discusses the development of the NaCl:K (10 –1 molar fraction of potassium) phosphor as dosimeter material for beta-radiation thermoluminescent dosimetry (TLD). The TLD grade NaCl:K(6T) material was prepared by annealing the NaCl:K powder obtained from aqueous solution by the method of recrystalization and annealed at 600°C for two hours in open air. It is observed that thermal glow curves of NaCl:K(6T) specimen exhibit well defined glow peak around 170°C alongwith a weaker peak at lower temperature. The high-temperature peak is found to grow supralinearily with increase in beta dose in the range 10–2×103 rad. Since the nature of glow curves under the influence of different doses remains more or less identical, it is believed that the phosphor does not undergo radiation damage and give high intrinsic TL around peak III. Examination of the system for fundamental dosimetry requirement shows that the NaCl:K(6T) material can be used as a suitable TLD material in beta radiation. 相似文献